ES2959316T3 - New polyester and compositions containing it - Google Patents

Abstract

This invention relates to a biodegradable polyester which is particularly suitable for use in the manufacture of mass produced articles characterized by excellent mechanical properties, in particular high tensile strength, elongation and tensile modulus, associated with a high barrier property against oxygen and carbon dioxide. (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

New polyester and compositions containing it

This invention relates to a biodegradable polyester characterized by substantial workability properties, even when blended with other polymers, and characterized in that it is capable of being processed into products such as, for example, films, fibers, nonwoven fabrics, sheets, articles. molded, injection molded, thermoformed, blow molded and expanded characterized by excellent mechanical properties, in particular, high tensile strength, elongation and tensile modulus, associated with high barrier properties against oxygen and carbon dioxide. This invention also relates to compositions and articles comprising said polyesters.

Over the years, polymeric materials have become more widespread due to their versatility, the fact that they can be easily worked and their low cost.

For example, among thermoplastic polymeric materials, the development of new polyesters has been of particular importance. In fact, polymeric materials of this type have found important use in the field of fibers, molded articles, injection and blow molding and film articles.

However, the increasing use of polymeric materials in increasingly technologically advanced fields of application requires the continuous development of new materials capable of guaranteeing increasingly higher performance during use.

For example, in the sector of thermoplastic polyesters for the production of packaging films, one of the greatest difficulties is to obtain products characterized by a good balance between toughness and deformability properties and the ability to withstand high loads.

On the other hand, in the molded articles sector one of the greatest difficulties is to guarantee high productivity, minimizing the tendency of manufactured articles to deform, for example, during the cooling stage in the mold (known as mold shrinkage) . ZOULONG YUet al.,"Chemosynthesis and characterization of fully biomass-based copolymers of ethylene glycol, 2,5-furandicarboxylic acid, and succinic acid", JOURNAL OF APPLIED POLYMER SCIENCE, JOHN WILEY & SONS, INC., USA, vol. 130, no. 2, October 15, 2013, for example, describe polyethylene copolymers of ethylene 2,5-furandicarboxylate-co-succinate (PEFS) of 2,5-furandicarboxylic acid (FDCA) and succinic acid with an FDCA composition of 11 .98-91.32 mol % synthesized by melt polycondensation in the presence of ethylene glycol using tetrabutyl titanate as a catalyst.

EP 2496630 A1 describes biodegradable aliphatic-aromatic polyesters comprising units derived from aliphatic dicarboxylic acids, polyfunctional aromatic acids and diols, wherein the units derived from polyfunctional aromatic acids comprise units derived from at least one phthalic diacid and at least one aromatic diacid. heterocyclic of renewable origin.

Document CN 103 570 925 A describes a biodegradable polyester comprising dimethyl adipate, hexanedioic acid, terephthalic acid, dimethyl terephthalate, ethylene glycol and furandicarboxylic acid dimethyl ester.

US 2013/095263 A1 describes polyester compositions prepared from 2,5-furandicarboxylic acid or an ester thereof or mixtures thereof, and 2,2,4,4-tetramethyl-1,3-cyclobutanediol.

WO 2013/062408 A1 describes a process for preparing a polymeric product having a 2,5-furandicarboxylate moiety within the polymer backbone for use in bottle, film or fiber applications.

The problem underlying the present invention is, therefore, to discover a new biodegradable polyester capable of guaranteeing high performance of the products obtained with it during use and, specifically, excellent workability and mechanical properties, especially , a high tensile strength, elongation and tensile modulus, along with a high barrier property against oxygen and carbon dioxide.

Starting from this problem, it has been surprisingly discovered that through the appropriate selection of the type and composition of the monomers it is possible to obtain a polyester that has the characteristics mentioned above.

Specifically, the present invention refers to a polyester that comprises:

a) a dicarboxylic component comprising, with respect to the total dicarboxylic component:

a1) 85-65 mol%, preferably 80-70 mol%, of units derived from 2,5-furandicarboxylic acid or an ester thereof;

a2) 15-35 mol%, preferably 20-30 mol%, of units derived from at least one saturated dicarboxylic acid selected from the group consisting of adipic acid, azelaic acid, sebacic acid, brazilic acid or an ester or derivative thereof, preferably azelaic acid;

a3) 0-15 mol%, preferably 0-10 mol%, of units that are derived from at least one aliphatic saturated dicarboxylic acid that is not the saturated dicarboxylic acid in component a2 and that are preferably selected from the group that consists of C2-C24 saturated carboxylic acids, preferably C4-C13, more preferably C4-C11, or esters thereof;

a4) 0-5 mol%, preferably 0.1-1 mol%, more preferably 0.2-0.7 mol%, of units derived from at least one unsaturated aliphatic dicarboxylic acid or an ester of the same;

b) a diol component comprising, with respect to the total diol component:

b1) 95-100% by mole, of units derived from 1,2-ethanediol;

b2) 0-5 mol% of units derived from at least one saturated aliphatic diol other than 1,2-ethanediol; b3) 0-5 mol%, preferably 0-3 mol%, of units derived from at least one unsaturated aliphatic diol.

The saturated aliphatic dicarboxylic acids other than the saturated dicarboxylic acid in component a2 (component a3 of the polyester according to the present invention) are preferably selected from C2-C24, preferably C4-C13, more preferably C4-C11 saturated dicarboxylic acids, their C1-C24 alkyl esters, preferably C1-C4, their salts and mixtures thereof. The unsaturated aliphatic dicarboxylic acids (component a4 of the polyester according to the present invention) are preferably selected from itaconic acid, fumaric acid, 4-methylenepimelic acid, 3,4-bis(methylene)nonanedioic acid, 5-methylenenonanedioic acid, their esters. of C1-C24 alkyl, preferably C1-C4, its salts and mixtures thereof. In a preferred embodiment of the present invention, the unsaturated aliphatic dicarboxylic acids comprise mixtures comprising at least 50 mol%, preferably more than 60 mol%, more preferably more than 65 mol%, of itaconic acid, its C1 esters -C24, preferably C1-C4. More preferably, the unsaturated aliphatic dicarboxylic acids comprise itaconic acid.

Regarding the saturated aliphatic diols that are not 1,2-ethanediol (component b2 of the polyester according to the invention), these are preferably selected from 1,2-propanediol, 1,3-propanediol, 1,4- butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, 2-methyl-1,3-propanediol, dianhydrosorbitol, dianhydromannitol, dianhydroiditol, cyclohexanediol, cyclohexanemethanediol, dialkylene glycols and polyalkylene glycols having a molecular weight of 100-4000, such as, for example, polyethylene glycol, polypropylene glycol and mixtures thereof. Preferably, the non-1,2-ethanediol diol component comprises at least 50 mol % of one or more diols selected from 1,3-propanediol or 1,4-butanediol. More preferably, said diol component comprises or consists of 1,4-butanediol.

With regard to unsaturated aliphatic diols (component b3 of the polyester according to the present invention), these are preferably selected from cis 2-butene-1,4-diol, trans 2-butene-1,4-diol, 2 -butin-1,4-diol, cis 2-penten-1,5-diol, trans 2-penten-1,5-diol, 2-pentin-1,5-diol, cis 2-hexen-1,6- diol, trans 2-hexen-1,6-diol, 2-hexin-1,6-diol, cis 3-hexen-1,6-diol, trans 3-hexen-1,6-diol, 3-hexin-1 ,6-diol.

In addition to the dicarboxylic component and the diol component, the polyesters of the composition according to the present invention preferably comprise repeating units derived from at least one hydroxy acid in an amount of 0-49%, preferably 0-30%, in moles with with respect to the total moles of the dicarboxylic component. Some examples of suitable hydroxy acids are glycolic, hydroxybutyric, hydroxycaproic, hydroxyvaleric, 7-hydroxyheptanoic, 8-hydroxycaproic or 9-hydroxynonanoic acid, lactic acid or lactides. Hydroxy acids may be inserted into the chain as such or may also have been previously reacted with diacids or diols.

Long molecules with two functional groups, including functional groups that are not in the terminal position, may also be present in amounts not exceeding 10 mol % with respect to the total moles of the dicarboxylic component. Some examples are dimeric acids, ricinoleic acid and acids that incorporate epoxy groups and also polyoxyethylenes with molecular weights between 200 and 10,000.

Diamines, amino acids and amino alcohols may also be present in percentages of up to 30 mol% with respect to the total moles of the dicarboxylic component.

In the course of the preparation of the polyester according to the present invention, one or more molecules with multiple functional groups can also advantageously be added in amounts of between 0.1 and 3 mol% with respect to the total moles of the dicarboxylic component. (including any hydroxy acid) in order to obtain branched products. Some examples of these molecules are glycerol, pentaerythritol, trimethylolpropane, citric acid, dipentaerythritol, triglycerides of acids, polyglycerols.

The molecular weight Pn of the polyesters of the composition according to the present invention is preferably >20000, more preferably >40000. Regarding the polydispersity index of the molecular weights, Pm/Pn, this is preferably between 1.5 and 10, more preferably between 1.6 and 5 and even more preferably between 1.8 and 2.7.

Molecular weights Pn and Pm can be measured by gel permeation chromatography (GPC). The determination can be carried out with the chromatography system maintained at 40 °C, using a set of three columns in series (particle diameter of 5 pm and porosities of 500 A, 10000 A and 100000 A, respectively), an index detector of refraction, hexafluoroisopropanol (HFIP) as eluent (flow rate of 1 ml/min), using poly(methyl methacrylate) as reference standard.

Preferably, the polyester having the composition according to the present invention has an inherent viscosity of more than 0.3 dl/g, preferably between 0.3 and 2 dl/g, more preferably between 0.4 and 1.2 dl /g (measured using an Ubbelohde viscometer in a 1:1 v/v dichloromethane-trifluoroacetic acid solution at a concentration of 0.5 g/dl at 25 °C).

The polyester having the composition according to the present invention has a glass transition temperature (Tg) of between 5 ° C and 60 ° C, measured by differential scanning calorimetry.

The polyesters according to the present invention are characterized by high barrier properties against oxygen and carbon dioxide.

Preferably, the polyesters according to the present invention have:

• an oxygen permeability barrier of less than 10 (cm<3>xmm)/(m<2>x24hxbar) measured at 23°C and 50% relative humidity in accordance with ASTM F2622-08, and

• a carbon dioxide permeability barrier of less than 35 (cm<3>xmm)/(m<2>x24hxbar) measured at 23°C and 50% relative humidity in accordance with ASTM F2476-05.

The polyester of the composition according to the present invention is biodegradable. According to the meaning of the present invention, biodegradable polyesters are biodegradable polyesters that have a relative biodegradability after 180 days of 90% or more with respect to microcrystalline cellulose according to ISO 14855-1. Preferably, according to the meaning of the present invention, the biodegradable polyesters are biodegradable polyesters in accordance with the EN 13432 standard.

The polyester according to the present invention can be synthesized according to any of the processes known in the current state of the art. In particular, they can be advantageously obtained by a polycondensation reaction.

Advantageously, the synthesis process can be carried out in the presence of a suitable catalyst. Suitable catalysts include, for example, organometallic tin compounds, for example stanoic acid derivatives, titanium compounds, for example orthobutyl titanate, aluminum compounds, for example triisopropyl Al, antimony compounds, zinc and zirconium and mixtures thereof.

The polyester according to the present invention can also be used as a blend which can also be obtained by reactive extrusion processes using one or more polymers of synthetic or natural origin, which may or may not be biodegradable, as well as one or more different components. .

In a preferred embodiment, the present invention relates to compositions comprising:

i) 1-99%, preferably 5-95%, by weight with respect to the sum of the components i.-v. of at least one polyester according to the present invention;

ii) 99-1%, preferably 95-5%, by weight with respect to the sum of the components i.-v. of at least one polymer that is not the polyester according to the present invention (component i.), of synthetic or natural origin, which may or may not be biodegradable;

iii) 0-5%, preferably 0-0.5%, by weight with respect to the sum of components i.-v. of at least one cross-linking agent and/or a chain extender comprising at least one compound having two and/or multiple functional groups including isocyanate, peroxide, carbodiimide, isocyanurate, oxazoline, epoxide, anhydride or divinyl ether groups and mixtures of the same;

iv) 0-50%, preferably 0-40%, by weight with respect to the sum of the components i.-v. of at least one charge;

v) 0-30% by weight with respect to the sum of the components i.-v. of vegetable fibers.

As for the polymers that are not the polyester according to the present invention, of synthetic or natural origin, which may or may not be biodegradable (component ii of the composition according to the present invention), these are advantageously selected from the group consisting of polyhydroxyalkanoates, vinyl polymers, non-polyester diacid diol polyesters, i.e., polyamides, polyurethanes, polyethers, polyureas, polycarbonates and mixtures thereof.

Regarding the polyhydroxyalkanoates, these are preferably selected from the group consisting of lactic acid polyesters, poly-£-caprolactone, polyhydroxybutyrate, polyhydroxybutyrate-valerate, polyhydroxybutyratepropanoate, polyhydroxybutyrate-hexanoate, polyhydroxybutyrate-decanoate, polyhydroxybutyrate-dodecanoate, polyhydroxybutyrate- hexadecanoate, polyhydroxybutyrate-octadecanoate, poly-3-hydroxybutyrate-4-hydroxybutyrate. Preferably, the polyhydroxyalkanoate of the composition comprises at least 80% by weight of one or more lactic acid polyesters. In a preferred embodiment, said lactic acid polyesters are selected from the group consisting of poly-L-lactic acid, poly-D-lactic acid, the poly-D-L-lactic acid stereocomplex, copolymers comprising more than 50% in moles of said lactic acid polyesters, or mixtures thereof. Particularly preferred are lactic acid polyesters containing at least 95% by weight of repeating units derived from L-lactic or D-lactic acids or combinations thereof having a molecular weight Pm greater than 50,000 and a shear viscosity. between 50 and 500 Pa.s., preferably between 100 and 300 Pa.s (measured according to ASTM D3835 at T = 190 °C, shear rate = 1000 s-1, D = 1 mm, LID = 10).

In an especially preferred embodiment of the invention, the lactic acid polyester comprises at least 95% by weight of units derived from L-lactic acid, <5% repeating units derived from D-lactic acid, has a melting point within in the range of 135-170 °C, a glass transition temperature (Tg) in the range of 55-65 °C and an MFR in the range of 1-50 g/10 min (measured in accordance with ISO 1133- 1 at 190 °C and 2.16 kg). Some examples of marketed lactic acid polyesters that have these properties are, for example, Ingeo™ Biopolymer 4043D products, brands 3251D and 6202D.

Of the vinyl polymers, the preferred ones are: polyethylene, polypropylene, their copolymers, poly(vinyl alcohol), poly(vinyl acetate), poly(ethyl vinyl acetate) and poly(ethylene vinyl alcohol), polystyrene, chlorinated vinyl polymers, polyacrylates. .

Among the chlorinated vinyl polymers, those included herein are, in addition to poly(vinyl chloride), poly(vinylidene chloride), poly(ethylene chloride), poly(vinyl chloride-vinyl acetate) , poly(vinylethylene chloride), poly(vinyl chloride-propylene), poly(vinyl chloride-styrene), poly(vinyl chloride-isobutylene) and copolymers in which poly(vinyl chloride) represents more than 50 % in moles. Said copolymers can be random, block or alternating copolymers.

As for non-polyester diacid diol polyesters i. According to the present invention, these are preferably selected from the group consisting of polyesters comprising:

a) a dicarboxylic component comprising, with respect to the total dicarboxylic component:

a11) 0-40%, preferably 0-20%, in moles of one or more aromatic diacids, their esters or salts; a12) 60-100%, preferably 80-100%, in moles of one or more aliphatic diacids, their esters or salts; either

a21) 40-95%, preferably 45-80%, in moles of one or more aromatic diacids, their esters or salts;

a22) 5-60%, preferably 20-55%, in moles of one or more aliphatic diacids, their esters or salts; either

a31) 95-100%, preferably 97-100%, in moles of one or more aromatic diacids, their esters or salts;

a32) 0-5%, preferably 0-3%, in moles of one or more aliphatic diacids, their esters or salts;

b) a diol component comprising units derived with respect to the total diol component:

b1) 95-100 mol% of units derived from at least one saturated aliphatic diol;

b2) 0-5 mol% of units derived from at least one unsaturated aliphatic diol.

Preferably, the aromatic dicarboxylic acids, the saturated aliphatic dicarboxylic acids, the unsaturated aliphatic dicarboxylic acids, the saturated aliphatic diols and the unsaturated aliphatic diols for said polyesters are selected from those described above for the polyester according to the present invention (component i. ). More preferably, said diacid diol polyesters which are other than polyester i. They are selected from the group consisting of poly(ethylene terephthalate), poly(propylene terephthalate), poly(butylene terephthalate), poly(ethylene 2,5-furandicarboxylate), poly(propylene 2,5-furandicarboxylate), poly(butylene 2,5-furandicarboxylate) and block or random copolymers of the type poly(alkylene 2,5-furandicarboxylate-co-alkylene terephthalate), poly(alkylene alkylate), of the poly(alkylene terephthalate- alkylene co-alkylate) or poly(alkylene 2,5-furandicarboxylate-alkylene co-alkylate). Some preferred examples of non-polyester diacid diol polyesters i. are selected from the group consisting of: poly(1,4-butylene succinate), poly(1,2-ethylene succinate), poly(1,4-butylene adipate), poly(1,2-ethylene adipate ), poly(1,4-butylene azelate), poly(1,2-ethylene azelate), poly(1,4-butylene sebacate), poly(1,2-ethylene-co-succinate 1,4 -butylene), poly(1,2-ethylene adipate-co-1,4-butylene adipate), poly(1,2-ethylene azelate-co-1,4-butylene azelate), poly(butylene sebacate 1,2-ethyleneco-sebacate of 1,4-butylene), poly(1,2-ethylene-co-adipate of 1,4-butylene succinate), poly(1,2-ethyleneco-azelate of 1, 4-butylene), poly(1,2-ethylene succinate-1,4-butylene co-sebacate), poly(1,2-ethylene adipate-1,4-butylene cosuccinate), poly(1,4-butylene adipate ,2-ethylene-co-1,4-butylene azelate), poly(1,2-ethylene adipate-1,4-butylene cosebacate), poly(1,2-ethylene-co-succinate) ,4-butylene), poly(1,2-ethylene azelate-1,4-butylene coadipate), poly(1,2-ethylene azelate-co-1,4-butylene sebacate), poly(1,4-butylene sebacate 1,2-ethylene-cosuccinate 1,4-butylene), poly(1,2-ethylene-co-1,4-butylene adipate), poly(1,2-ethylene-co-1,4-sebacate butylene azelate), poly(1,4-butylene adipate-1,4-butylene co-succinate), poly(1,4-butylene azelate-1,4-butylene cosuccinate), poly(1,4-butylene sebacate 1,4-butylene,4-butylene-co-succinate, poly(1,4-butylene succinate, 1,4-butylene co-azelate), poly(1,4-butylene adipate) ,4-butylene-co-1,4-butylene terephthalate, poly(1,4-butylene sebacate-co-1,4-butylene terephthalate), poly(1,4-butylene-co-terephthalate) 1,4-butylene), poly(1,4-butylene brasylate-co-1,4-butylene terephthalate), poly(1,4-butylene succinate-co-1,4-butylene terephthalate), poly(1,4-butylene adipate-co-1,4-butylene sebacate-co-1,4-butylene terephthalate), poly(1,4-butylene azelate-co-1,4-butylene sebacate -1,4-butylene co-terephthalate, poly(1,4-butylene adipate-co-1,4-butylene azelate-1,4-butylene co-terephthalate), poly(1,4-succinate 1,4-butylene-co-sebacate, 1,4-butylene-co-terephthalate, poly(1,4-butylene-co-terephthalate), butylene), poly(1,4-butylene azelate-co-succinate, 1,4-butylene-co-terephthalate, 1,4-butylene), poly(1,4-butylene-co-2,5-furandicarboxylate 1,4-butylene), poly(1,4-butylene-co-2,5-furandicarboxylate, 1,4-butylene sebacate), poly(1,4-butylene-co-2,5-furandicarboxylate), 1,4-butylene), poly(1,4-butylene-co-2,5-furandicarboxylate), poly(1,4-butylene-co-2,5-furandicarboxylate), 1,4-butylene), poly(1,4-butylene adipate-co-sebacate, 1,4-butylene-co-2,5-furandicarboxylate, 1,4-butylene azelate), poly(1,4-butylene azelate) 1,4-butylene-co-2,5-furandicarboxylate butylene-co-sebacate, 1,4-butylene-co-2-poly(1,4-butylene-co-azelate) 1,4-butylene,5-furandicarboxylate), poly(1,4-butylene-co-succinate, 1,4-butyleneco-2,5-furandicarboxylate), poly(1,4-butylene adipate 1,4-butylene-4-butylene-co-succinate, 1,4-butylene-co-2,5-furandicarboxylate, poly(1,4-butylene-co-succinate) 1,4-butylene co-2,5-furandicarboxylate), its copolymers and mixtures.

In another preferred embodiment of the present invention, said non-polyester diacid diol polyesters i. are selected from the group consisting of:

(A) polyesters comprising repetitive units derived from aromatic dicarboxylic acids of the phthalic acid type, preferably terephthalic acid, aliphatic dicarboxylic acids and aliphatic diols (AAPE-A) characterized by a content of aromatic units between 35 and 60% in moles, preferably between 40 and 55 mol% with respect to the total moles of the dicarboxylic component. AAPE-A polyesters are preferably selected from: poly(1,4-butylene adipate-co-1,4-butylene terephthalate), poly(1,4-butylene sebacate-co-1,4-butylene terephthalate ), poly(1,4-butylene azelate-co-1,4-butylene terephthalate), poly(1,4-butylene brasylate-co-1,4-butylene terephthalate), poly(1,4-butylene succinate), 4-butylene-co-1,4-butylene terephthalate), poly(1,4-butylene adipate-co-1,4-butylene-co-sebacate, 1,4-butylene terephthalate), poly(butylene azelate) 1,4-butylene-co-sebacate, 1,4-butylene-co-terephthalate, poly(1,4-butylene-co-azelate, 1,4-butylene-co-terephthalate) 1,4-butylene succinate), poly(1,4-butylene succinate-co-sebacate, 1,4-butylene-co-terephthalate, 1,4-butylene terephthalate), poly(1,4-butylene adipate-co-succinate 1,4-butylene-co-1,4-butylene terephthalate), poly(1,4-butylene-co-sebacate 1,4-butylene-co-1,4-butylene terephthalate).

(B) polyesters comprising repeating units derived from heterocyclic dicarboxylic aromatic compounds, preferably 2,5-furanedicarboxylic acid, aliphatic dicarboxylic acids and aliphatic diols (AAPE-B) characterized by a content of aromatic units between 50 and 80% in moles, preferably between 60 and 75 mol%, with respect to the total moles of the dicarboxylic component. AAPE-B polyesters are preferably selected from: poly(1,4-butylene adipate-co-2,5-furandicarboxylate, 1,4-butylene), poly(1,4-butylene-co-2,5-furandicarboxylate sebacate). 1,4-butylene brasylate, poly(1,4-butylene-co-2,5-furandicarboxylate), poly(1,4-butylene-co-2,5-furandicarboxylate) ,4-butylene), poly(1,4-butylene succinate-co-1,4-butylene 2,5-furandicarboxylate), poly(1,4-butylene adipate-co-1,4-butylene sebacate -1,4-butylene co-2,5-furandicarboxylate), poly(1,4-butylene azelate-1,4-butylene co-sebacateco-2,5-furandicarboxylate), poly (1,4-butylene adipate-co-azelate, 1,4-butylene-co-2,5-furandicarboxylate), poly(1,4-butylene-co-succinate 1, 1,4-Butylene-4-butylene-co-2,5-furandicarboxylate, 1,4-butylene-co-2,5-furandicarboxylate poly(1,4-butylene-co-succinate) -butylene), poly(1,4-butylene-co-succinate, 1,4-butylene-co-2,5-furandicarboxylate).

With regard to the polyamides in the composition according to the present invention, these are preferably selected from the group consisting of polyamides 6 and 6,6, polyamides 9 and 9,9, polyamides 10 and 10,10, polyamides 11 and 11,11, polyamide 12 and 12,12 and their combinations of type 6/9, 6/10, 6/11, 6/12, their mixtures and both random and block copolymers.

Preferably, the polycarbonates of the composition according to the present invention are selected from the group consisting of poly(alkylene carbonates), more preferably poly(ethylene carbonates), poly(propylene carbonates), poly(butylene carbonates) , their mixtures and random and block copolymers.

Among the polyethers, those selected from the group consisting of polyethylene glycols, polypropylene glycols, polybutylene glycols, their copolymers and their mixtures having molecular weights of 70,000 to 500,000 are preferred.

In the composition according to the present invention, the cross-linking agent and/or chain extender (component iii.) improves the stability to hydrolysis and is selected from compounds having two and/or multiple functional groups that include isocyanate groups, peroxide , carbodiimide, isocyanurate, oxazoline, epoxide, anhydride or divinyl ether and mixtures thereof. Preferably, the cross-linking and/or chain extender agent comprises at least one compound having two and/or multiple functional groups including isocyanate groups. More preferably, the cross-linking and/or chain extender agent comprises at least 25% by weight of one or more compounds having two and/or multiple functional groups including isocyanate groups. Especially preferred are mixtures of compounds having two and/or multiple functional groups including isocyanate groups, with compounds having two and/or multiple functional groups including epoxy groups, more preferably comprising at least 75% by weight of compounds that They have two and/or multiple functional groups that include isocyanate groups.

Compounds with two or multiple functional groups including isocyanate groups are preferably selected from p-phenylene p-diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4-diphenylmethane diisocyanate, 1,3-phenylene-4-chloro, 1,5-naphthalene diisocyanate, 4,4-diphenylene diisocyanate, 3,3'-dimethyl-4,4-diphenylmethane diisocyanate, 3-methyl-4,4' diisocyanate -diphenylmethane, diphenyl ester diisocyanate, 2,4-cyclohexane diisocyanate, 2,3-cyclohexane diisocyanate, 1-methyl 2,4-cyclohexyl diisocyanate, 1-methyl 2,6-cyclohexyl diisocyanate, bis-(cyclohexyl isocyanate )methane, 2,4,6-toluene triisocyanate, 2.4.4-diphenyl ether triisocyanate, polymethylene-polyphenyl-polyisocyanates, methylenediphenyl diisocyanate, triphenylmethane triisocyanate, 3,3'-ditolylene-4,4-diisocyanate, bis- 4,4'-methylene (2-methylphenyl isocyanate), hexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,2-cyclohexylene diisocyanate and mixtures thereof. In a preferred embodiment, the compound that includes isocyanate groups is 4,4-diphenylmethane diisocyanate.

With regard to compounds having two or multiple functional groups incorporating peroxide groups, these are preferably selected from benzoyl peroxide, lauroyl peroxide, isononanoyl peroxide, di-(t-butylperoxyisopropyl)benzene, t-butyl peroxide , dicumyl peroxide, alpha,alpha'-di(t-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, t-butylcumyl peroxide, di-t-butylperoxide, 2, 5-dimethyl-2,5-di(t-butylperoxy)hex-3-yne, di(4-t-butylcyclohexyl peroxydicarbonate), dicetyl peroxydicarbonate, dimyristyl peroxydicarbonate, 3,6,9-triethyl-3,6 ,9-trimethyl-1,4,7-triperoxonane, di(2-ethylhexyl) peroxydicarbonate and their mixtures.

Compounds with two or multiple functional groups including carbodiimide groups that are preferably used in the composition according to the present invention are selected from poly(cyclooctylenecarbodiimide), poly(1,4-dimethylenecyclohexylenecarbodiimide), poly(cyclohexylenecarbodiimide), poly(ethylenecarbodiimide). ), poly(butylenecarbodiimide), poly(isobutylenecarbodiimide), poly(nonylenecarbodiimide), poly(dodecylenecarbodiimide), poly(neopentylenecarbodiimide), poly(1,4-dimethylenephenylenecarbodiimide), poly(2,2',6,6'-tetraisopropyldiphenylenecarbodiimide) (Stabaxol® D), poly(2,4,6-triisopropyl-1,3-phenylenecarbodiimide) (Stabaxol® P-100), poly(2,6-diisopropyl-1,3-phenylenecarbodiimide) (Stabaxol® P), poly(tolylcarbodiimide), poly(4,4'-diphenylmethanecarbodiimide), poly(3,3'-dimethyl-4,4'-biphenylenecarbodiimide), poly(p-phenylenecarbodiimide), poly(mphenylenecarbodiimide), poly(3,3' -dimethyl-4,4'-diphenylmethanecarbodiimide), poly(naphthalenecarbodiimide), poly(isophoronecarbodiimide), poly(cumenecarbodiimide), p-phenylene-bis(ethylcarbodiimide), 1,6-hexamethylenebis(ethylcarbodiimide), 1,8-octamethylene- bis(ethylcarbodiimide), 1,10-decamethylene-bis(ethylcarbodiimide), 1,12-dodecamethylene-bis(ethylcarbodiimide) and their mixtures.

Some examples of compounds with two or multiple functional groups that include epoxide groups that can be used advantageously in the composition according to the present invention are all polyepoxides from epoxylated oils and/or styrene-glycidyl ether-methyl methacrylate, glycidyl ether- methyl methacrylate, included in a range of molecular weights between 1000 and 10000 and having an epoxy number per molecule in the range of 1 to 30 and preferably between 5 and 25, and epoxides selected from the group comprising: diethylene glycol diglycidyl ether , polyethylene glycol diglycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, 1,2-epoxybutane, polyglycerol polyglycidyl ether, isoprene diepoxide and cycloaliphatic diepoxides, 1,4-cyclohexandimethanol diglycidyl ether, glycidyl 2-methylphenyl ether, glycerol propoxylaotriglycidyl ether , 1, 4-butanediol diglycidyl ether, sorbitol polyglycidyl ether, glycerol diglycidyl ether, metaxylene diamine tetraglycidyl ether and bisphenol A diglycidyl ether and their mixtures.

Catalysts can also be used together with the compounds with two or multiple functional groups including isocyanate, peroxide, carbodiimide, isocyanurate, oxazoline, epoxide, anhydride and divinyl ether groups in the composition according to the present invention to increase the reactivity of the groups. reagents. Fatty acid salts are preferably used, even more preferably calcium and zinc stearates, in the case of polyepoxides.

In an especially preferred embodiment of the invention, the cross-linking agent and/or the chain extender of the composition comprises compounds that include isocyanate groups, preferably 4,4-diphenylmethane diisocyanate and/or that include carbodiimide groups and/or that include epoxide groups, preferably of the styreneglycidyl ether-methyl methacrylate type.

In the composition according to the present invention, the filler (component iv.) helps to improve the dimensional stability and is preferably selected from kaolin, barites, clay, talc, calcium and magnesium, iron and lead carbonates, aluminum hydroxide, diatomaceous earth, aluminum sulfate, barium sulfate, silica, mica, titanium dioxide, wollastonite, starch, chitin, chitosan, alginates, proteins, such as gluten, zein, casein, collagen, gelatin, natural gums, rosinic acids and Their derivatives.

The term starch means all types of starch, that is: flour, native starch, hydrolyzed starch, destructured starch, gelatinized starch, plasticized starch, thermoplastic starch, biofillers comprising complexed starch or mixtures thereof. Particularly suitable according to the invention are starches such as potato, corn, tapioca and pea.

Starches that can be easily destructured and have high initial molecular weights, such as, for example, potato or corn starch, have proven to be especially advantageous.

The starch may be present as is or in a chemically modified form, such as, for example, in the form of starch esters with a degree of substitution between 0.2 and 2.5, hydroxypropylate starch, or starch modified with fatty chains. .

For destructured starch the present document refers to the indications included in the patents EP-0 118 240 and EP-0 327505, and said starch means starch that has been processed to be substantially free of the so-called "Maltese crosses" under a microscope optical in polarized light and the so-called "ghosts" under a phase contrast optical microscope.

Advantageously, the starch is destructured by means of an extrusion process at temperatures between 110 and 250 °C, preferably 130-180 °C, at pressures preferably between 0.1 and 7 MPa, preferably 0.3-6 MPa, preferably providing a specific energy of more than 0.1 kWh/kg during said extrusion.

The destructuring of the starch preferably takes place in the presence of 1-40% by weight with respect to the weight of the starch of one or more plasticizers selected from water and polyols having 2 to 22 carbon atoms. Regarding water, this can also be what is naturally present in starch. Among the polyols, preferred are polyols having 1 to 20 hydroxyl groups containing 2 to 6 carbon atoms, their ethers, thioethers and organic and inorganic esters. Some examples of polyols are glycerin, diglycerol, polyglycerol, pentaerythritol, ethoxylated polyglycerol, ethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, sorbitol monoacetate, sorbitol diacetate, sorbitol monoethoxylated , diethoxylated sorbitol and mixtures thereof. In a preferred embodiment, the starch is destructured in the presence of glycerol or a plasticizer mixture comprising glycerol, more preferably containing between 2 and 90% by weight of glycerol. Preferably, the destructured and cross-linked starch according to the present invention comprises between 1 and 40% by weight of plasticizers with respect to the weight of the starch.

When present, the starch in the composition is preferably in the form of particles having a circular or elliptical cross section or a cross section that in any case can be compared to an ellipse having an arithmetic mean diameter of less than 1 micrometer and preferably less than 0.5 pm average diameter, measured taking into account the major axis of the specific particle.

In a preferred embodiment of the present invention, the filler comprises talc, calcium carbonate or mixtures thereof, present in the form of particles having an arithmetic mean diameter of less than 10 micrometers, measured taking into account the long axis of the particles. In fact, it has been discovered that fillers of the aforementioned type that are not characterized by said arithmetic mean diameter improve significantly less the disintegration characteristics, during industrial composting, of the molded objects that compose them. Without wishing to be bound by any specific theory, it is considered that when used in the compositions according to the present invention, said fillers stratify and agglomerate during the molding stage, thus slowing down the action of the agents responsible for the disintegration of the articles. molded.

In the composition according to the present invention, the plant fibers (component v.) are preferably selected from cellulose fibers, wood flour, cannabis fibers, lignocellulose residues from raw materials of plant origin, such as, for example , thistle and sunflower plants, and cut grass.

The polymer composition according to the present invention preferably comprises up to 30% by weight of plant fiber (component v.). In fact, it has been discovered that said content has the effect of significantly improving the disintegration properties of the polymer composition, while allowing the manufacture of articles that have a high heat distortion temperature under load and a particularly high dimensional stability, thus allowing compositions to be prepared that are also devoid of fillers.

In a preferred embodiment, the composition according to the present invention comprises 5 to 25% by weight of vegetable fiber and contains no fillers (component iv.). In particular, this plant fiber content is especially suitable for use in the composition according to the present invention in injection molding techniques.

"Dimensional stability" refers to the ability of an object to maintain its original shape over time and after annealing treatment.

It has also been unexpectedly discovered that the use of plant fibers having a length/diameter ratio (i.e., L/D) < 40, preferably LID < 30 and even more preferably LID < 20, have proven to be especially advantageous, because in addition to contributing to the aforementioned heat distortion high temperature and dimensional stability properties, does not result in excessive increases in tensile modulus or significant decreases in the deformation of the polymer composition in the event of failure, or an appreciable reduction in its fluidity in molten state.

Especially preferred compositions according to the present invention are biodegradable. In the present invention, when it is indicated that the compositions are biodegradable this means that they are characterized by a disintegration greater than 90% in 90 days in accordance with the ISO20200:2004 standard. Some especially preferred examples of biodegradable compositions according to the present invention are:

- Compositions A, which comprise, with respect to the sum of components i.-v.:

i) 20-60%, preferably 25-55%, more preferably 25-50% by weight of at least one biodegradable polyester i.;

ii) 20-70%, preferably 25-65%, by weight of at least one polyhydroxyalkanoate;

iii) 0-5%, preferably 0-0.5%, of at least one cross-linking agent and/or a chain extender comprising at least one compound having two and/or multiple functional groups including isocyanate groups , peroxide, carbodiimide, isocyanurate, oxazoline, epoxide, anhydride or divinyl ether and mixtures thereof;

iv) 0-50%, preferably 3-45%, more preferably 5-40% by weight of at least one filler; v) 0-30% by weight of vegetable fibers.

- Compositions B, which comprise, with respect to the sum of components i.-v.:

i) 20-60%, preferably 25-55%, more preferably 25-50% by weight of at least one biodegradable polyester i.;

ii) 20-70%, preferably 25-65%, by weight of at least one aliphatic diacid diol polyester; iii) 0-5%, preferably 0-0.5%, of at least one cross-linking agent and/or a chain extender comprising at least one compound having two and/or multiple functional groups including isocyanate groups , peroxide, carbodiimide, isocyanurate, oxazoline, epoxide, anhydride or divinyl ether and mixtures thereof;

iv) 0-50%, preferably 3-45%, more preferably 5-40% by weight of at least one filler; v) 0-30% by weight of vegetable fibers.

- Compositions C, which comprise, with respect to the sum of components i.-v.:

i) 20-60%, preferably 25-55%, more preferably 25-50% by weight of at least one biodegradable polyester i.;

ii) 20-70%, preferably 25-65%, by weight of at least one aliphatic aromatic diacid diol polyester;

iii) 0-5%, preferably 0-0.5%, of at least one cross-linking agent and/or a chain extender comprising at least one compound having two and/or multiple functional groups including isocyanate groups , peroxide, carbodiimide, isocyanurate, oxazoline, epoxide, anhydride or divinyl ether and mixtures thereof;

iv) 0-50%, preferably 3-45%, more preferably 5-40% by weight of at least one filler; v) 0-30% by weight of vegetable fibers.

In addition to components i.-v., the composition according to the present invention also preferably contains at least one other component selected from the group consisting of plasticizers, UV stabilizers, lubricants, nucleating agents, surfactants, antistatic agents, pigments, flame retardant agents, compatibilizing agents, lignin, organic acids, antioxidants, anti-mold agents, waxes and process adjuvants.

With regard to plasticizers, in the composition according to the present invention there are preferably present, in addition to the plasticizers preferably used for the preparation of the destructured starch and described above, one or more plasticizers selected from the group consisting of phthalates, such as, for example, diisononyl phthalate, trimellitates, such as, for example, esters of trimellitic acid with C4-C20 monoalcohols preferably selected from the group consisting of n-octanol and ndecanol, and aliphatic esters having the following structure:

Ri -O-C(O)-R<4>-C(O)-[-O-R<2>-O-C(O)-Ra-C(O)-]m-O-Ra

where:

R1 is selected from one or more groups comprising H, saturated and unsaturated linear and branched alkyl moieties of the C1-C24 type, polyol moieties esterified with C1-C24 monocarboxylic acids;

R2 comprises -CH<2>-C(CH<3>)<2>-CH<2>- and C2-C8 alkylene groups, and comprises at least 50 mol % of said -CH<2>-C groups (CH<3>)<2>-CH<2>-;

R3 is selected from one or more of the groups comprising H, saturated and unsaturated linear and branched alkyl moieties of the C1-C24 type, polyol moieties esterified with C1-C24 monocarboxylic acids;

R4 and R5 are the same or different and comprise one or more C2-C22 alkylenes, preferably C2-C11, more preferably C4-C9, and comprise at least 50 mol% C7 alkylenes,

m is a number between 1 and 20, preferably 2-10, more preferably 3-7. Preferably, in said esters, at least one of the groups R1 and/or R3 comprises polyol moieties esterified with at least one C1-C24 monocarboxylic acid selected from the group consisting of stearic acid, palmitic acid, 9-ketostearic acid, 10- ketostearic acid and mixtures thereof, preferably in amounts >10 mol%, more preferably >20%, even more preferably >25 mol% with respect to the total amounts of R1 and/or R3 groups. Examples of aliphatic esters of this type are described in Italian patent application MI2014A000030 and in PCT applications PCT/EP2015/050336, PCT/EP2015/050338.

When present, the selected plasticizers are preferably present up to 10% by weight with respect to the total weight of the composition.

The lubricants are preferably selected from esters and metal salts of fatty acids such as, for example, zinc stearate, calcium stearate, aluminum stearate and acetyl stearate. Preferably, the composition according to the present invention comprises up to 1% by weight of lubricants, more preferably up to 0.5% by weight, with respect to the total weight of the composition.

Examples of nucleating agents include the sodium salt of saccharin, calcium silicate, sodium benzoate, calcium titanate, boron nitride, isotactic polypropylene, and low molecular weight PLA. These additives are preferably added in amounts of up to 10% by weight and more preferably between 2 and 6% by weight with respect to the total weight of the composition.

Pigments can also be added if necessary, for example, titanium dioxide, clays, copper phthalocyanine, iron silicates, oxides and hydroxides, carbon black and magnesium oxide. These additives are preferably added up to 10% by weight.

The production process of the compounds comprising the polyester according to the present invention can be carried out according to any of the processes known in the current state of the art. Advantageously, said compositions are obtained through extrusion processes in which the polymeric components are mixed in a molten state. When extruding the composition, the components may be introduced all together or one or more of them may be introduced separately along the extruder.

The polyester according to the present invention is extremely suitable for use, alone or in the form of compositions of the type described above, for example, in numerous practical applications for the manufacture of products such as, for example, films, fibers, non-woven fabrics. fabrics, sheets, molded, thermoformed, blown or expanded articles and laminated articles, including the use of the extrusion coating technique.

This invention also relates to articles comprising the polyester according to the present invention.

Some examples of products comprising the polyester according to the present invention are:

- films, monooriented and bioriented and multilayered with other polymeric materials;

- films for use in the agricultural sector, such as mulch films;

- stretch films, including transparent films for food, for bales in agriculture and for wrapping garbage;

- bags and tubs for the collection of organic products, such as the collection of food scraps and grass clippings; - thermoformed food containers, both single-layer and multi-layer, such as, for example, containers for milk, yogurt, meat, drinks, etc.;

- coatings obtained by the extrusion coating technique;

- multilayer laminates with layers of paper, plastics, aluminum, metallized films;

- expanded or expandable spheres for the production of parts formed by sintering;

- expanded and semi-expanded products, including expanded blocks formed from pre-expanded particles; - expanded sheets, thermoformed expanded sheets, containers obtained from these for packaging food;

- general containers for fruits and vegetables;

- composite materials with gelatinized, destructured and/or complexed starch, natural starch, flours, other fillers of natural vegetable or inorganic origin, as fillers;

- fibers, microfibers, composite fibers with a core comprising rigid polymers, such as PLA, PET, PTT, etc., and an outer covering of the material of the invention, deblens composite fibers, fibers having various cross sections from round to multi-lobed , flocculated fibers, fabrics and spunbonded or thermobonded nonwovens for the healthcare, healthcare, agricultural and fashion sectors.

It can also be used in applications as a substitute for plasticized PVC.

The polyester according to the present invention and the compositions comprising it are also especially suitable for use in injection molding and thermoforming and spinning.

In fact, the characteristics of the polyester according to the present invention allow injection molded or thermoformed articles to be manufactured that have a high heat deflection temperature (HDT) and a high dimensional stability. For example, the polyester according to the present invention and the compositions containing it are especially suitable for the production of disposable cutlery, plates and glasses, rigid containers, capsules for dispensing beverages, preferably hot drinks, lids and covers, and food containers that can be heated in conventional ovens and microwaves.

In a preferred embodiment of the present invention, said thermoformed articles comprise at least one layer A comprising or consisting of a composition comprising or consisting of the polyester according to the present invention and at least one layer B comprising at least a polymer selected from the group comprising diacid diol polyesters and hydroxy acid polyesters, and are preferably characterized by a mutual arrangement of said layers A and B selected from A/B, A/B/A and B/A/B. In another especially preferred embodiment, said layer B comprises a lactic acid polyester.

As far as the thermoforming molding process is concerned, the polyester according to the present invention and the compositions containing it can be molded according to methods known to those skilled in the art, starting, for example, from sheets, plates or films, under pressure or vacuum. This invention also relates to said sheets, plates or films comprising the polyester according to the present invention and compositions including it used for the production of molded articles by thermoforming.

Typical thermoforming operating conditions provide, for example, for a heating time of the sheet, plate or film of 5 to 8 seconds until softening, and molding times of between 15 and 20 seconds.

As far as injection molding is concerned, the polyester according to the present invention and the compositions containing it have the additional advantage that they can be introduced into conventional machinery without requiring substantial changes in normal working conditions, compared to other conventional polymers such as, for example, polyethylene, polypropylene, polystyrene and Bs. Preferably, in the case of objects with a maximum thickness of the order of 1 millimeter, these can be molded using a melting temperature of 200-240 °C, an oleodynamic pressure of 7 to 110 bars, a cooling time of 3 to 15 seconds. and a cycle time of 10 to 30 seconds.

In a particularly preferred embodiment, injection molded articles comprising the polyester according to the present invention are subjected to hot annealing treatments at temperatures between 70 and 150°C. This invention also relates to articles obtained by annealing treatments (known as annealed products).

Such annealing treatments can advantageously be carried out in an unconfined environment at constant temperature, for example within ovens. In this case, the annealing treatments are preferably carried out at temperatures between 80 and 150 °C with residence times of 30 s to 60 min, preferably 40 s to 30 min and even more preferably 40 s to 5 min, this being particularly advantageous from a production point of view. The specific conditions to be used will vary depending on the dimensions of the object to be annealed and the level of heat resistance required by the application. In general, in the case of thick objects it is preferable to use higher temperatures or longer residence times.

Such annealing treatments can also be carried out in confined environments, for example, within preheated molds at a constant temperature, preferably 80 to 100 °C for 1 to 5 minutes. The specific conditions to be used will vary depending on the dimensions of the object undergoing annealing treatment. In general, in the case of large thicknesses, it is preferable to use longer residence times.

The invention will now be illustrated through a series of embodiments that are only intended to be examples and do not limit the scope of protection of this patent application.

Examples

Polyester synthesis

The reactants 2,5-furandicarboxylic acid, azelaic acid or sebacic acid and 1,2-ethanediol and the esterification catalyst (Tyzor TE®) were loaded into a 25 liter geometric steel reactor provided with oil heating, a column of distillation, a vacuum line with a distillation system and mechanical stirring, in the proportions shown in table 1.

The reactor was sealed and 3 vacuum/nitrogen cycles were carried out to remove any oxygen present. Subsequently, the stirrer was turned on and the temperature was gradually raised to 220 °C for a period of 1 hour during which the water from the esterification process began to distill. The temperature was then raised to 238°C for approximately one more hour.

The distillation was allowed to proceed for 1 hour at 238°C, at the end of which the apparent conversion was 100% or more.

Vacuum was applied gradually from atmospheric pressure to 100 mbar for approximately 30 minutes to complete the esterification.

At the end of the esterification step, the reactor was brought back to atmospheric pressure with nitrogen and then the polymerization catalyst (1000 ppm tetraorthobutyl zirconate, ToBZ) was added, the melt temperature was maintained at 238 °C. and the pressure was gradually reduced to less than 2 mbar over a time of approximately 30 minutes.

The reaction continued for 4 h maintaining the melt temperature at 238 °C until the desired inherent viscosity was achieved.

The material was then discharged in the form of filaments through a spinner, cooled in a water bath and granulated.

Determination of barrier properties against oxygen and carbon dioxide and biodegradation tests The barrier properties have been determined in 60-90 pm cast films made with the polyesters prepared according to examples 1-4.

The films were prepared using polymer solution casting techniques. Polyesters prepared according to Examples 1-4 were dissolved in a hexafluoroisopropanol/dichloromethane mixture, coated on a substrate, then annealed at temperatures between 60 and 120 °C and with residence times between 1 and 30 hours, to remove any residual traces of solvent.

Barrier properties have been determined by permeability measurements performed on an Extrasolution Multiperm permeability meter at 23°C and 50% relative humidity in accordance with ASTM F2622-08 for oxygen and ASTM F2476- 05 for carbon dioxide.

The biodegradation tests were carried out in accordance with the ISO14855-1 standard "Determination of the final aerobic biodegradability of plastic materials under controlled composting conditions. Method according to the analysis of carbon dioxide generated. Part 1: General method", with the polyesters prepared according to examples 1-4.

T l 2: D rmin i n ^ l r i rr r ^ n i r i n

Claims (12)

1. A polyester comprising: a) a dicarboxylic component comprising, with respect to the total dicarboxylic component: a1) 85-65 mol% of units derived from 2,5-furandicarboxylic acid or one of its esters; a2) 15-35% by mole of units derived from at least one saturated dicarboxylic acid selected from the group comprising adipic acid, azelaic acid, sebacic acid, brasilic acid or an ester or derivative thereof; a3) 0-15 mol % of units derived from at least one aliphatic saturated dicarboxylic acid that is not the saturated dicarboxylic acid in component a2; a4) 0-5 mol% of units derived from at least one unsaturated aliphatic dicarboxylic acid or an ester thereof; b) a diol component comprising, with respect to the total diol component: b1) 95-100 mol% of units derived from 1,2-ethanediol; b2) 0-5 mol% of units derived from at least one saturated aliphatic diol that is not 1,2-ethanediol; b3) 0-5 mol% of units derived from at least one unsaturated aliphatic diol. 2. A polyester according to claim 1, wherein said saturated aliphatic dicarboxylic acid (component a3) is selected from C2-C24 saturated dicarboxylic acids, their C1-C24 alkyl esters, their salts and their mixtures. 3. A polyester according to any of claims 1 or 2, wherein said dicarboxylic acid saturated in component a2 is azelaic acid. 4. A polyester according to claim 3, wherein said dicarboxylic acid in component a3 is selected from the group consisting of succinic acid, 2-ethylsuccinic acid, glutaric acid, 2-methylglutaric acid, adipic acid, pimelic acid, suberic, sebacic acid, undecanedioic acid, dodecanedioic acid, brazilic acid and their C1-C24 alkyl esters. 5. A polyester according to any one of claims 1 to 4, wherein said saturated aliphatic diol other than 1,2-ethanediol (component b2) is selected from the group consisting of 1,2-propanediol, 1,3 -propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol , 1,12-dodecanediol, 1,13-tridecanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, 2-methyl-1,3-propanediol, dianhydrosorbitol, dianhydromannitol, dianhydroiditol, cyclohexanediol, cyclohexanemethanediol, dialkylene glycols and polyalkylene glycols having a molecular weight of 100 to 4000 measured by gel permeation chromatography, polypropylene glycol and mixtures thereof. 6. A polyester according to any one of claims 1 to 5, characterized by an inherent viscosity of more than 0.3 dl/g (measured with an Ubbelohde viscometer in a 1:1 dichloromethane-trifluoroacetic acid solution v /v at a concentration of 0.5 g/dl at 25 °C). 7. Films, fibers, nonwoven fabrics, sheets, molded, thermoformed, blow-molded articles and blow-molded laminates comprising the polyester according to any one of claims 1 to 6. 8. A composition comprising the polyester according to any one of claims 1 to 6. 9. A composition according to claim 8, comprising, with respect to the sum of components i.-v.: i) 1-99% by weight of at least one polyester according to any one of claims 1 to 6; ii) 99-1% by weight of at least one polymer other than polyester according to any one of claims 1 to 6, of synthetic or natural origin, which may or may not be biodegradable; iii) 0-5% by weight of at least one cross-linking agent and/or a chain extender comprising at least one compound having two and/or multiple functional groups including isocyanate, peroxide, carbodiimide, isocyanurate, oxazoline groups , epoxide, anhydride or divinyl ether and mixtures thereof; iv) 0-50% by weight of at least one filler; v) 0-30% by weight of vegetable fibers. 10. Films, fibers, nonwoven fabrics, sheets, molded, injection molded, thermoformed, blow molded, expanded and laminated articles comprising the composition according to claim 9. 11. Injection molded articles comprising the composition of claim 9. 12. Injection molded articles according to claim 11, suitable for the production of disposable cutlery, plates and glasses, rigid containers, capsules for dispensing beverages, preferably hot beverages, lids and covers, and heatable food containers. in conventional and microwave ovens.